Looks like what you are using is just fine. What I have been using is shown in pics. Minwax (for large craters) Bondo ( for fine work) {not the two part Bondo} Aero Gloss (thinned 50% ,several aplications) to strengthen "soft balsa" Epoxy (thinned 50% w/alcohol ,as a final step on inside)
I know,that was more than you asked for.

Sig dope is a far better product to use on boats then Aero Gloss. It fills grain much better. Clear works well over stained wood like the mahogany. Balsa filler will turn milky when dry, don't use on stained wood.Filler is ok anywhere else. Put on several coats then sand, put on several more coats and sand lightly between coats.Dope will shrink as it dries and will show the grain hence the need for a filler first.Some use a tissue doped to the hull (preferably silkspan used for model aircraft) and put on wet. Aero Gloss is no good for this type of work.

Sig is the brand name, they also make aircraft kits and have other hardware mostly for aircraft. Around here the R/C Buyers warehouse in Nashua NH carries it but I have no idea where you'd get it. It is thicker than Aero Gloss and has better pigmentation. I've used it for years and Testers dope before that.( Testers hasn't made it in years though) You can thin dope with acetone. use woodfiller for the seams and balsa filler to seal the grain of the wood.

Aero Gloss 43-4 Thinner It soaks in well ,give it time to dry,it shrinks and now your (weak balsa ) is "locked" there for your fill/ finish .
Immagine a dry kitchen sponge.... You want a nice finish .....Fill the top surface ..Sand....Paint ....Lovely!!!!! Now,wet the sponge.
Moisture gets every where. So,several aplications of 50/50 will give your sponge(pithy balsa) the internal strength that it lacks.

OBW

PS There are perhaps more than a dozen products that will work .Make sure all products from start (glue/cement/CA) to finish (Color/clear coat) are compattable. After that you argue Ford/GM/Chrysler etc etc.

On a side note. My motivation behind this build is that my Dad built this same model when I was two years old. Back in 1961. He would take me down to a dam in Willoughby Ohio and cruise the boat. The boat went over the dam on one occasion and my Dad claimed it was someone on a CB Radio who interfered with the RC signal. Luckily It wasn't too badly damaged. In the early Ninties my Mom sold it in a Garage Sale.